Samsung laptop date/time resets - not bios battery!

Hi! I wonder if anyone can help me with this as I have no idea what could be causing this. I have played with it so much I can be fairly precise about its behaviour so please excuse me if I overdo it on the description.

I have a Samsung RC-520 (less than a year old) which resets the time and date back to oct 2011 00:00 when rebooted. This only occurs if its been of for more than 5 seconds, any less and it remembers. I immediately assumed a dead BIOS battery was to blame and because the customer wrongly lead me to believe it was within warranty I dissasembled the laptop and replaced it. This did not solve the problem.

So here are the other things I have tried:

Reset BIOS back to default.
Updated to 'Firmware' 1.0.0.2 via windows installer.
Replaced hard drive, ram and removed optical drive (clutching straws )
Tried with battery out / without mains power.
Reset the time in Windows 7

Here are some things I have noticed:
To test whether or not the BIOS was resetting I changed the lower 3 boot orders from 4:USB FDD, 5:USB HDD, 6:NETWORK to 4:NETWORK, 5:USB FDD, 6:USB HDD. This does not change, so as far as I know, only the time and date do.
If the time/date reset (laptop off for more than 5 secs) then the laptop does not start properly 1st time. Instead I get a blank screen and the power led lights and that's it for 15 secs. After that the power button led comes on and I hear the optical drive engage but still nothing on screen. So then I have to hold the power button down for 5 secs to power off and then (as long as I'm faster than 5 secs) press the power button to find it turns on and boots to windows as normal.

So does this ring a bell with anyone? Maybe I should take the BIOS battery out again and leave it overnight with no power to completely reset it? Can't see how this could be hardware. Very strange!

if i recall removing the battery and leaving it for 15-30 min does a hard reset or some such.

odd behaviour indeed though, have you checked for root kits?

No, I haven't, I will try that today with malwarebytes and combofix.
Thanks for the suggestion, will let you know what happens.

It didn't work. Malwarebytes, spybot, combofix, sophos anti-rootkit and kaspersky-tdskiller all found nothing!

Could this actually be a motherboard fault?

Bump! Anyone else have any ideas? It must be fixable.
This is one of those problems that contradicts all related knowledge learned in an IT career.
It's unlikely to be hardware because its ONLY the time that resets and not other BIOS settings but its equally unlikely that the BIOS software itself screwing up in that way.

I feel that I need to reflash the BIOS but Samsung don't seem to offer that as a download. There is a 'firmware' update but that is done through windows and didn't work anyway. http://www.samsung.com/uk/support/mo...lDownload=true

Pretty sure I'm not going mad here. Pretty sure.

This is a bit extreme, but you have tried to reinstall windows? I'm betting thats it's a corrupted file, registry string of some kind. If nothing else try repairing the OS...and if that doesn't work then reinstall the OS. Or at the very least run sfc /scannow command.

SFC /SCANNOW Command - System File Checker

bass, surely windows gets it's time from the bios and doesn't affect the bios settings? it shouldn't be able to interact with the bios in that way either without a program like a bios updater.

could be wrong lol not a clue anymore on this one.

Yes, the problem occurs even if the hard drive is removed. Those boot device settings are still the same as when I changed them though. I think this thing is possessed!